These are very cool indeed, I'd do a search myself but I have a mountain load of Batman books to sift through.

__________________A few of the Marvel Superheroes are somewhat niche characters that aren't extremely versatile, thus they don't have a lot of longevity potential. For example, Namor is a water guy, Silver Surfer is a space guy, Dr. Strange is a magic guy, and so on.

I don't imagine Batman was pumping people full of bullets in the cartoon..

It's just your garden variety ray gun.

"The Savage Time" is one of those alternate timeline stories in which someone (in this case, Vandal Savage) has gone back in time and changed history. In this new timeline, the Axis Powers won World War II. Batman is the leader of a resistance movement against a fascist regime led by Savage.

That's my long way of saying that this isn't the Bruce that we know and love. He's very similar, but the experiences that led him to this point were different than the "normal" timeline.

That being said, Batman grabbed the gun from one of his freedom fighters to threaten the Justice League (he wasn't a member in this timeline), as he wasn't sure whether they were friends or enemies. However, he didn't fire the gun, nor did he use one during any other scene in this episode, so he may have had "our Bruce's" aversion to firearms.